It is more cost effective to treat all suspected cases of nail fungus with oral terbinafine without first performing any diagnostic tests than obtaining laboratory confirmation, an analysis has found.

The US researchers said that guidelines encouraged healthcare professionals to seek confirmatory testing before starting systemic therapy for fungal nail infections. In the United Kingdom the National Institute for Health and Care Excellence also advises doctors to confirm the diagnosis with positive microscopy or positive culture before starting treatment.

Studies from the 1990s concluded that this approach was cost effective, but there has …